Food soils are the result of adhesive bonds between food and surface substrates such as, for example, stainless steel, glass, plastic and aluminum. Carbohydrates, fats, proteins, and mineral salts from food sources contribute to the deposition of food soils on surfaces. Milk, for example, typically contains inorganic cationic salts of various minerals such as calcium, magnesium and iron together with such anions as carbonate, sulfate and oxalate. Bicarbonates, sulfates, and chlorides of calcium or magnesium present in hard water can neutralize detergents, decrease rinsability and create films on equipment. Mineral precipitation contributes to the disadvantageous effects of food soil deposition on various types of systems including, for example, food processing equipment (milking equipment, evaporators, fermentors) and warewashers and household appliances.
The most common deposits forming in food processing applications are typically comprised of some combination of starches and sugars, oils and fats, and proteinaceous materials. These deposits become difficult to remove when subjected to high temperatures, as heat can partially degrade the chemical structure of fats and proteins, reducing their solubility in water. Milk soils commonly occurring in dairy processing applications, consist primarily of butterfat, whey proteins, and lactose sugars. These soils can be particularly challenging to remove, as the components, primarily the fat and protein, require significantly different chemical approaches for removal from equipment surfaces.
The presence of food soils and precipitates in pipelines, for example, can increase system operating costs by reducing liquid flow, expediting corrosion, fostering the growth of bacteria and algae, and acting as an insulating layer that diminishes heat transfer. While all of these factors are deleterious, the problem of inefficient heat transfer is compounded by the fact that soils build quickly near heated surfaces where concentrations of cations and anions become supersaturated.
chlorinated alkaline detergents used, for example, to clean food processing equipment, normally consist of a blend of sodium hypochlorite, sodium hydroxide, and water conditioning agents to improve cleaning efficacy in hard water. The formulas are most frequently circulated for clean-in-place (CIP) cleaning and are required to be low or no foaming. Surfactants such as non-ionic and anionic detergents reduce the surface tension of liquid and substantially increase the effectiveness of the cleaning process. However, the use of conventional surfactants, in conjunction with standard chlorinated alkaline detergents results in a physical incompatibility by generating foam. Additionally for formulation into concentrated chlorinated alkaline detergents, most surfactants are incompatible with either the strong alkaline, basic conditions or high electrolyte content, or react with the hypochlorite. The production of foam can be deleterious for certain applications such as clean in place formulations. Production of foam interferes with equipment function by, for example, clogging pipelines, creating pressure variations, and by remaining in the system for extended periods of time.